Many wearable articles are designed to be fastened about a wearer via a hook-and-loop fastening system. A hook-and-loop fastening system is exemplified by the VELCRO system; it includes a hooks component, which is a patch of usually plastic material having a dense pattern of small flexible upstanding hook structures, T-shaped structures, arrow-shaped structures, mushroom-shaped structures or other structures formed thereon; and a loops component, which is a patch or section of substrate material having a dense disposition of upstanding fiber loops or other sections of fibers connected to the substrate in such as way as to extend away from the substrate while having ends attached to the substrate. When the hooks component is brought into contact with the loops component under pressure (usually applied by the fingers), the individual hook structures engage loops structures and catch therein. Substantial attachment strength, especially resistive to separation in a shearing mode, may be obtained by the cumulative effect of many hooks on the hooks patch engaging many loops on the loops component. Since their introduction, hook-and-loop fastening systems have been refined and specialized in design for varying applications, and have proven popular and effective. They provide a quick and convenient mechanism for fastening one member to another member in a way that can conveniently and effectively substitute for older types of fastening or attachment systems such as buttons, snaps, ties, zippers, etc. Additionally, various hooks designs have been created for engaging various types of loops components. In some cases hooks designs are suitable for engaging and hooking into the fibers of various types of fabrics without the necessity of a specially provided loops component.
Currently, many disposable diapers include hook-and-loop fastening systems. A typical disposable diaper may include a central chassis having front and rear regions, and a pair of fastening members or ears extending laterally from the rear region. Each of the fastening members may have disposed thereon a patch of hooks. The outside of the front region may have disposed thereon a corresponding patch of loops material, often called the “landing zone.” The diaper may be applied to a wearer by positioning the rear region of the diaper beneath the wearer while in a reclining position, wrapping the front region of the diaper between the wearer's legs and up over the front of the wearer's lower torso, wrapping each of the fastening members about a hip, and attaching each fastening member via the hooks patch to the landing zone, thereby forming a pant-like structure about the wearer. Various types of specialized hook and loops materials have been developed specifically for use on disposable diapers.
More recently, it has been found that a nonwoven material having suitable characteristics and features, may serve as a suitable loops material; see, for example, U.S. Pat. No. 7,789,870. The cited patent discloses a nonwoven formed of bicomponent fibers. The bicomponent fibers have longitudinal components formed of differing polyolefins. The bicomponent fibers are formed by ejecting or extruding the differing polyolefins in a molten state under pressure, from specially adapted spinnerets situated in banks along a nonwoven web forming line. The spinnerets separately form the longitudinal components and then urge them together while the polymers are still molten, thereby forming bicomponent fibers having two distinct longitudinal components. When the longitudinal components are appropriately configured with respect to one another within the fiber, as a result of differing properties of the differing polyolefins including differing rates and/or extents of contraction upon cooling, after exiting the spinnerets the bicomponent fibers curl or “crimp” as they cool. When such crimped fibers are subsequently laid down to form a nonwoven batt and then consolidated and bonded in an appropriate pattern, they form attached loop-like structures that may make the resulting nonwoven web suitable for use as a loops material in some applications, including disposable diapers.
By competitive necessity, the business of manufacturing disposable diapers is a relatively capital-intensive, high-volume, low margin-per-article business. Consequently, any improvement in the product or its manufacture that can save even to a small extent on costs of materials or manufacture without sacrificing performance, or any improvement that enhances performance without increasing cost, can provide significant competitive advantages to the manufacturer. Improvements to nonwoven materials used to form loops components of landing zones, and improvements in fastening systems including such nonwovens, are no exception. While current technologies including the above-cited '870 patent have provided a nonwoven web material that serves satisfactorily as loops material in certain applications, further improvements in the fastening/holding capabilities and/or reductions in cost would be advantageous in these applications and others.